DESCRIPTION (from Applicant's Abstract) Chronic, uncontrolled uveitis often leads to intraocular synechiae and irreversible retinal damage. The long-term objective of this research plan is to reestablish ocular immune privilege to the uveitic eye by reimposing expression of the immunomodulating factor alpha-melanocyte stimulating hormone (a-MSH) in the ocular microenvironment. It has been shown that the normal but not uveitic aqueous humor contains a-MSH and other factors which are known to suppress immunogenic inflammation. The first specific aim will study the effects of a-MSH injected into eyes of mice with experimental autoimmune uveitis (EAU). Experiments will be designed to monitor the clinical course of disease as well as objectively evaluate histopathology of treaed and untreated tissue. Cytokine assays of treated and untreated aqueous humor, immunohistochemistry, and experiments testing for immunosuppressive activity of aqueous humor of treated mice will also characterize the effects of local a-MSH injections. The second aim will examine the effects of the gene encoding a-MSH transfected into uveitic eyes. Viral and non-viral encoding the gene for a-MSH will be tested. Preliminary data suggest that subconjunctival injections of naked DNA plasmid vectors expressing a-MSH suppress the severity and incidence of EAU. This aim will involve experiments demonstrating suppression of EAU following vector transfection. Aqueous humor from transfected eyes will be characterized to show reexpression of immunosuppressive factors by cytokine analysis and aqueous humor suppression of activated T cells in vitro. Confirmation of transfection will be accomplished by fluorescent microscopy of ocular tissue transfected with vectors labeled with GFP. Clinical disease monitoring and ocular histopathology will also be examined. Discovering specific effects of a-MSH on EAU will assist in identifying its role in restoration of ocular immune privilege and expand on the basic knowledge in the field of gene therapy.